mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
213 lines
5.0 KiB
213 lines
5.0 KiB
/* |
|
* arch/xtensa/kernel/time.c |
|
* |
|
* Timer and clock support. |
|
* |
|
* This file is subject to the terms and conditions of the GNU General Public |
|
* License. See the file "COPYING" in the main directory of this archive |
|
* for more details. |
|
* |
|
* Copyright (C) 2005 Tensilica Inc. |
|
* |
|
* Chris Zankel <[email protected]> |
|
*/ |
|
|
|
#include <linux/clk.h> |
|
#include <linux/of_clk.h> |
|
#include <linux/errno.h> |
|
#include <linux/sched.h> |
|
#include <linux/time.h> |
|
#include <linux/clocksource.h> |
|
#include <linux/clockchips.h> |
|
#include <linux/interrupt.h> |
|
#include <linux/module.h> |
|
#include <linux/init.h> |
|
#include <linux/irq.h> |
|
#include <linux/profile.h> |
|
#include <linux/delay.h> |
|
#include <linux/irqdomain.h> |
|
#include <linux/sched_clock.h> |
|
|
|
#include <asm/timex.h> |
|
#include <asm/platform.h> |
|
|
|
unsigned long ccount_freq; /* ccount Hz */ |
|
EXPORT_SYMBOL(ccount_freq); |
|
|
|
static u64 ccount_read(struct clocksource *cs) |
|
{ |
|
return (u64)get_ccount(); |
|
} |
|
|
|
static u64 notrace ccount_sched_clock_read(void) |
|
{ |
|
return get_ccount(); |
|
} |
|
|
|
static struct clocksource ccount_clocksource = { |
|
.name = "ccount", |
|
.rating = 200, |
|
.read = ccount_read, |
|
.mask = CLOCKSOURCE_MASK(32), |
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS, |
|
}; |
|
|
|
struct ccount_timer { |
|
struct clock_event_device evt; |
|
int irq_enabled; |
|
char name[24]; |
|
}; |
|
|
|
static int ccount_timer_set_next_event(unsigned long delta, |
|
struct clock_event_device *dev) |
|
{ |
|
unsigned long flags, next; |
|
int ret = 0; |
|
|
|
local_irq_save(flags); |
|
next = get_ccount() + delta; |
|
set_linux_timer(next); |
|
if (next - get_ccount() > delta) |
|
ret = -ETIME; |
|
local_irq_restore(flags); |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* There is no way to disable the timer interrupt at the device level, |
|
* only at the intenable register itself. Since enable_irq/disable_irq |
|
* calls are nested, we need to make sure that these calls are |
|
* balanced. |
|
*/ |
|
static int ccount_timer_shutdown(struct clock_event_device *evt) |
|
{ |
|
struct ccount_timer *timer = |
|
container_of(evt, struct ccount_timer, evt); |
|
|
|
if (timer->irq_enabled) { |
|
disable_irq_nosync(evt->irq); |
|
timer->irq_enabled = 0; |
|
} |
|
return 0; |
|
} |
|
|
|
static int ccount_timer_set_oneshot(struct clock_event_device *evt) |
|
{ |
|
struct ccount_timer *timer = |
|
container_of(evt, struct ccount_timer, evt); |
|
|
|
if (!timer->irq_enabled) { |
|
enable_irq(evt->irq); |
|
timer->irq_enabled = 1; |
|
} |
|
return 0; |
|
} |
|
|
|
static DEFINE_PER_CPU(struct ccount_timer, ccount_timer) = { |
|
.evt = { |
|
.features = CLOCK_EVT_FEAT_ONESHOT, |
|
.rating = 300, |
|
.set_next_event = ccount_timer_set_next_event, |
|
.set_state_shutdown = ccount_timer_shutdown, |
|
.set_state_oneshot = ccount_timer_set_oneshot, |
|
.tick_resume = ccount_timer_set_oneshot, |
|
}, |
|
}; |
|
|
|
static irqreturn_t timer_interrupt(int irq, void *dev_id) |
|
{ |
|
struct clock_event_device *evt = &this_cpu_ptr(&ccount_timer)->evt; |
|
|
|
set_linux_timer(get_linux_timer()); |
|
evt->event_handler(evt); |
|
|
|
/* Allow platform to do something useful (Wdog). */ |
|
platform_heartbeat(); |
|
|
|
return IRQ_HANDLED; |
|
} |
|
|
|
void local_timer_setup(unsigned cpu) |
|
{ |
|
struct ccount_timer *timer = &per_cpu(ccount_timer, cpu); |
|
struct clock_event_device *clockevent = &timer->evt; |
|
|
|
timer->irq_enabled = 1; |
|
snprintf(timer->name, sizeof(timer->name), "ccount_clockevent_%u", cpu); |
|
clockevent->name = timer->name; |
|
clockevent->cpumask = cpumask_of(cpu); |
|
clockevent->irq = irq_create_mapping(NULL, LINUX_TIMER_INT); |
|
if (WARN(!clockevent->irq, "error: can't map timer irq")) |
|
return; |
|
clockevents_config_and_register(clockevent, ccount_freq, |
|
0xf, 0xffffffff); |
|
} |
|
|
|
#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT |
|
#ifdef CONFIG_OF |
|
static void __init calibrate_ccount(void) |
|
{ |
|
struct device_node *cpu; |
|
struct clk *clk; |
|
|
|
cpu = of_find_compatible_node(NULL, NULL, "cdns,xtensa-cpu"); |
|
if (cpu) { |
|
clk = of_clk_get(cpu, 0); |
|
if (!IS_ERR(clk)) { |
|
ccount_freq = clk_get_rate(clk); |
|
return; |
|
} else { |
|
pr_warn("%s: CPU input clock not found\n", |
|
__func__); |
|
} |
|
} else { |
|
pr_warn("%s: CPU node not found in the device tree\n", |
|
__func__); |
|
} |
|
|
|
platform_calibrate_ccount(); |
|
} |
|
#else |
|
static inline void calibrate_ccount(void) |
|
{ |
|
platform_calibrate_ccount(); |
|
} |
|
#endif |
|
#endif |
|
|
|
void __init time_init(void) |
|
{ |
|
int irq; |
|
|
|
of_clk_init(NULL); |
|
#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT |
|
pr_info("Calibrating CPU frequency "); |
|
calibrate_ccount(); |
|
pr_cont("%d.%02d MHz\n", |
|
(int)ccount_freq / 1000000, |
|
(int)(ccount_freq / 10000) % 100); |
|
#else |
|
ccount_freq = CONFIG_XTENSA_CPU_CLOCK*1000000UL; |
|
#endif |
|
WARN(!ccount_freq, |
|
"%s: CPU clock frequency is not set up correctly\n", |
|
__func__); |
|
clocksource_register_hz(&ccount_clocksource, ccount_freq); |
|
local_timer_setup(0); |
|
irq = this_cpu_ptr(&ccount_timer)->evt.irq; |
|
if (request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL)) |
|
pr_err("Failed to request irq %d (timer)\n", irq); |
|
sched_clock_register(ccount_sched_clock_read, 32, ccount_freq); |
|
timer_probe(); |
|
} |
|
|
|
#ifndef CONFIG_GENERIC_CALIBRATE_DELAY |
|
void calibrate_delay(void) |
|
{ |
|
loops_per_jiffy = ccount_freq / HZ; |
|
pr_info("Calibrating delay loop (skipped)... %lu.%02lu BogoMIPS preset\n", |
|
loops_per_jiffy / (1000000 / HZ), |
|
(loops_per_jiffy / (10000 / HZ)) % 100); |
|
} |
|
#endif
|
|
|